Bad User Agent Configuration by crowdsecurity | CrowdSec Hub

Bad User Agent

Attack scenariohttp:scanMITRE T1595

By: crowdsecurity
Version: 1.2
Name: crowdsecurity/http-bad-user-agent
Remediation: Ban

Detect usage of bad User Agent

Install with a top-level collection

16 collections include it

sudo cscli collections install crowdsecurity/aws-cloudfront

Installs 2 parsers and 47 scenarios, via HTTP - Generic Protection.

View AWS CloudFront →

Installation

sudo cscli scenarios install crowdsecurity/http-bad-user-agent

Then reload CrowdSec: sudo systemctl reload crowdsec

Configuration

Hover a line or a note to see what each field does.

scenarios/crowdsecurity/http-bad-user-agent.yaml· 26 linesGitHub

1type: leaky1
2format: 2.0
3#debug: true
4name: crowdsecurity/http-bad-user-agent
5description: "Detect usage of bad User Agent"
6filter: 'evt.Meta.log_type in ["http_access-log", "http_error-log"] && RegexpInFile(evt.Parsed.http_user_agent, "bad_user_agents.regex.txt")'2
7data:
8  - source_url: https://hub-data.crowdsec.net/web/bad_user_agents.regex.txt
9    dest_file: bad_user_agents.regex.txt
10    type: regexp
11    strategy: LRU
12    size: 40
13    ttl: 10s
14capacity: 13
15leakspeed: 1m4
16groupby: "evt.Meta.source_ip"5
17blackhole: 2m6
18labels:
19  confidence: 1
20  spoofable: 0
21  classification:7
22    - attack.T1595
23  behavior: "http:scan"
24  label: "Bad User Agent"
25  service: http
26  remediation: true8

Installed on

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Documentation

Known bad user-agents

Detect known bad user-agents.

Bans after two requests per minute.